As the development of the LED technology in recent years, the light industry has changed a lot. More and more LEDs have been applied to lighting devices, especially to bulb lights. However, the LED light can't light-round as the incandescent lamp; the light emitted from LEDs has strong directivity. The lighting device with LED light bulbs always light uneven, and it is easy to generate a dark spot at a portion of one end of the bulb due to less light. What's more, because of the strong directivity, the LED bulb lighting device always light with small angle, which can't meet the lighting requirements.
Therefore, how to design a LED lighting device with uniform lighting effect and big lighting angle is the most urgent technical problem to be solved.